1[1]Thompson W H F. The nature of haemorrhoids. Br J Surg, 1975,62∶542.
2[2]Longo A. Treatment of heamorrhiodal disease by reduention of mucosa and hemorrhoidal prolapse with a circular suturing device: a new procedure. In; proceedings of the 6th World Congress of Endoscopic Surgery. Bologna: Monduzzi Editiore, 1998.777.
3[3]Gould R P. Sennsory innervational zone. Acta Path Microbiol Scand, 1997,187∶337.